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SICK WATER?
THE CENTRAL ROLE OF WASTEWATER MANAGEMENT IN SUSTAINABLE DEVELOPMENT
A RAPID RESPONSE ASSESSMENT

1


This report, compiled by GRID-Arendal has been an interagency collaboration led by UNEP and UN-HABITAT in partnership with members of UN Water.

Corcoran, E., C. Nellemann, E. Baker, R. Bos, D. Osborn,
H. Savelli (eds). 2010. Sick Water? The central role of wastewater management in sustainable development. A Rapid Response Assessment. United Nations Environment Programme, UN-HABITAT, GRID-Arendal. www.grida.no
ISBN: 978-82-7701-075-5
Printed by Birkeland Trykkeri AS, Norway
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A RAPID RESPONSE ASSESSMENT

SICK WATER?

THE CENTRAL ROLE OF WASTEWATER MANAGEMENT IN SUSTAINABLE DEVELOPMENT

Emily Corcoran (Editor in chief)
Christian Nellemann
Elaine Baker
Robert Bos
David Osborn
Heidi Savelli


4


JOINT STATEMENT

The statistics are stark: Globally, two million tons of sewage, industrial and agricultural
waste is discharged into the world’s waterways and at least 1.8 million children under five
years-old die every year from water related disease, or one every 20 seconds.
Over half of the world’s hospitals beds are occupied with people
suffering from illnesses linked with contaminated water and
more people die as a result of polluted water than are killed by
all forms of violence including wars.
The impact on the wider environment is no less striking. An
estimated 90 per cent of all wastewater in developing countries
is discharged untreated directly into rivers, lakes or the oceans.
Such discharges are part of the reason why de-oxygenated dead
zones are growing rapidly in the seas and oceans. Currently an
estimated 245 000 km2 of marine ecosystems are affected with
impacts on fisheries, livelihoods and the food chain.
The climate is also being impacted: Wastewater-related emissions of methane, a powerful global warming gas, and another

called nitrous oxide could rise by 50 per cent and 25 per cent
respectively between 1990 and 2020.
Already, half of the world’s population lives in cities, most of
which have inadequate infrastructure and resources to address
wastewater management in an efficient and sustainable way.
Twenty-one of the world’s 33 megacities are on the coast where
fragile ecosystems are at risk. Without urgent action to better
manage wastewater the situation is likely to get worse: By 2015,
the coastal population is expected to reach approximately 1.6
billion people or over one fifth of the global total with close to
five billion people becoming urban dwellers by 2030. By 2050
the global population will exceed nine billion.
Some of these trends are inevitable. However the world does
have choices in terms of the quantity and the quality of dis-

charges to rivers and seas if a sustainable link is made from
farms, rural areas and cities to the ecosystems surrounding
them.
In some cases, investments in improved sanitation and water
treatment technologies can pay dividends. In other cases investments in the rehabilitation and restoration of nature’s water purification systems—such as wetlands and mangroves—
offer a cost effective path.
UNEP and UN-Habitat are increasing our cooperation across
several fronts including meeting the wastewater challenge.
This report is one fruit of that collaboration.
Investing in clean water will pay multiple dividends from overcoming poverty to assisting in meeting the Millennium Development Goals. It also makes economic sense. According to a
recent report from the Green Economy Initiative, every dollar
invested in safe water and sanitation has a pay back of US$3 to
US$34 depending on the region and the technology deployed.
Meeting the wastewater challenge is thus not a luxury but a
prudent, practical and transformative act, able to boost public

health, secure the sustainability of natural resources and trigger
employment in better, more intelligent water management.

Achim Steiner
Executive Director, UNEP

Anna Tibaijuka
Executive Director, UN-HABITAT
5


PREFACE

The wastewater challenge is not
only a threat, but a challenge
where we can find opportunities
for green employment, social
well-being and ecological health

The United Nations Secretary-General’s Advisory Board on Water and Sanitation (UNSGAB) is committed to accelerating progress on the Millennium Development Goal
targets for water and sanitation.
UNSGAB collaborates with others to galvanize action and foster new initiatives. One of our initiatives for improving basic
sanitation coverage was the UN-backed International Year on
Sanitation (IYS) in 2008. By all accounts, the IYS was a success. It triggered an honest, concrete and productive public
discussion about expanding access to sanitary toilets and improving hygiene while fostering political commitments to act.
UNSGAB now is working to ensuring that these IYS commitments are fulfilled. We also are building on this positive
momentum to widen the discussion to include the collection,
treatment and reuse of human, household, agricultural, storm
and industrial wastewater and run-off. More than 80 percent of
wastewater is discharged untreated into water bodies. This untreated wastewater is the missing link to meeting the sanitation

challenge. It has a material impact on human health, social and
economic development and ecosystem sustainability.
The 2009 Istanbul Ministerial Statement embodies a global
commitment to “further develop and implement wastewater collection, treatment and reuse.” This report aims to place wastewater on the international and national agenda by pointing out
that wastewater management provides opportunities not only
challenges. Now, more than ever, we must promote strategic fi6

nancial planning at the country level to maximize efficiency to
improve coverage in the water and sanitation sectors.
UNSGAB has gained valuable experience and understanding
that we will now bring to bear on improving wastewater management. Meeting this challenge will require new alliances and
we are happy to have collaborated with UNEP, UN-HABITAT
and UN Water in the development of this report. We are ready
to work with the global community to promote a new wastewater paradigm encompassing modular design, appropriate technology, and sustainable financing. For as the report “Sick water? The central role of wastewater management in sustainable
development” points out, the wastewater challenge is not only
a threat, but is a challenge where we can find opportunities for
green employment, social well-being and ecological health.

HRH, Prince Willem-Alexander of the Netherlands
Chair, UN Secretary-General’s Advisory Board on Water and
Sanitation


7


8


EXECUTIVE SUMMARY

The world is facing a global water quality crisis. Continuing population growth and urbanisation, rapid industralisation, and expanding and intensifying food production are all
putting pressure on water resources and increasing the unregulated or illegal discharge of
contaminated water within and beyond national borders. This presents a global threat to human health and wellbeing, with both immediate and long term consequences for efforts to
reduce poverty whilst sustaining the integrity of some of our most productive ecosystems.
There are many causes driving this crisis, but it is clear that freshwater and coastal ecosystems across the globe, upon which humanity has depended for millennia, are increasingly threatened. It is equally clear that future demands for water cannot be met unless
wastewater management is revolutionized.
Global populations are expected to exceed nine billion by 2050.
Urban populations may rise nearly twice as fast, projected to
nearly double from current 3.4 billion to 6.4 billion by 2050,
with numbers of people living in slums rising even faster, from
one to 1.4 billion in just a decade. Over a fifth of the global total, 1.6 billion people are expected to live by the coast by 2015.
Inadequate infrastructure and management systems for the increasing volume of wastewater that we produce are at the heart
of the wastewater crisis.
The way we produce our food uses 70–90 per cent of the available fresh water, returning much of this water to the system
with additional nutrients and contaminants. It is a domino effect as downstream agricultural pollution is joined by human
and industrial waste. This wastewater contaminates freshwater and coastal ecosystems, threatening food security, access to
safe drinking and bathing water and providing a major health
and environmental management challenge. Up to 90 per cent
of wastewater flows untreated into the densely populated coastal zone contributing to growing marine dead zones, which already cover an area of 245 000 km2, approximately the same
area as all the world’s coral reefs.

Contaminated water from inadequate wastewater management
provides one the greatest health challenges restricting development and increasing poverty through costs to health care and
lost labour productivity. Worldwide, almost 900 million people
still do not have access to safe water and some 2.6 billion, al9


most half the population of the developing world do not have
access to adequate sanitation. At least 1.8 million children under five years old die every year due to water related disease,
accounting for around 17 per cent of deaths in this age group.

Worldwide some 2.2 million people die each year from diarrhoeal disease. Poor hygiene and unsafe water is responsible
for around 88 per cent of all diarrhoeal incidents.
Under-dimensioned and aged wastewater infrastructure is already overwhelmed, and with predicted population increases
and changes in the climate the situation is only going to get
worse. Without better infrastructure and management, many
millions of people will continue to die each year and there will
be further losses in biodiversity and ecosystem resilience, undermining prosperity and efforts towards a more sustainable
future. A healthier future needs urgent global action for smart,
sustained investment to improve wastewater management.
Change is both essential and possible. As a part of the shift to
a green economy, the public sector including national, provincial and local governments must be more proactive in funding wastewater management, central to which will be issues
of equity and social justice. To find solutions we will need to
draw on a cocktail of existing and new policy approaches and
funding mechanisms, from better water quality legislation
and voluntary agreements, to market-based instruments and
partnership-based financing and management models bringing together the public and private sectors, not forgetting the
vital role of education.
Wise investments in wastewater management will generate
significant returns, as addressing wastewater is a key step in
10

reducing poverty and sustaining ecosystem services. Instead of
being a source of problems, well-managed wastewater will be
a positive addition to the environment which in turn will lead
to improved food security, health and therefore economy. One
fifth of the world’s population, or 1.2 billion people, live in areas
of water scarcity, and this is projected to increase to 3 billion
by 2025 as water stress and populations increase. There is no
option but to consider wastewater as part of the solution. To
be successful and sustainable, wastewater management must

be an integral part of rural and urban development planning,
across all sectors, and where feasible transcending political, administrative and jurisdictional borders. There are few, if any, areas where investments in integrated planning can sustainably
provide greater returns across multiple sectors than the development of water infrastructure and the promotion of improved
wastewater management.
The first part of this report addresses the critical challenges we
face in managing wastewater and considers the implications
for people and the environment across different sectors, and
how these may be influenced by issues such as population
growth, urbanization and climate change.
The second part looks at solutions and how these challenges can
be turned around. Finding appropriate solutions will require innovation at both ends of the pipe. Innovation to reduce the volume and contamination of wastewater produced, how to treat or
even reuse the waste, and how to do it in an affordable sustainable way. The report reviews how the production and treatment
cycle can be better understood and managed so that through
better investment and management major environmental, societal, and economic dividends can be achieved.


A healthier future needs
urgent global action for smart,
sustained investment to improve
wastewater management

KEY MESSAGES:

1

Wastewater production is rising

The global population is expected to exceed nine billion people
by 2050. Major growth will take place in developing countries,
particularly in urban areas that already have inadequate wastewater infrastructure. The financial, environmental and social

costs are projected to increase dramatically unless wastewater
management receives urgent attention.

2

Wise and immediate investment will generate
multiple future benefits

Immediate, targeted and sustained investments should take
multiple forms. They should be designed to (i) reduce the volume and extent of water pollution through preventative practices; (ii) capture water once it has been polluted; (iii) treat
polluted water using appropriate technologies and techniques
for return to the environment; (iv) where feasible safely reuse
and recycle wastewater thereby conserving water and nutrients; and (v) provide a platform for the development of new
and innovative technologies and management practices. If investments such as these are scaled up appropriately they will
generate social, economic and environmental dividends far
exceeding original investments for years to come.

3

Improved sanitation and wastewater management are central to poverty reduction and improved human health

The poor are affected first and foremost by this global crisis.
Over half of the world’s hospital beds are occupied by people
suffering from water related diseases. Diarrhoeal diseases make
up over four per cent of the global disease burden, 90 percent
of which is linked to environmental pollution, a lack of access
to safe drinking water and sanitation. Comprehensive and sustained wastewater management in combination with sanitation
and hygiene is central to good health, food security, economic
development and jobs. In terms of public spending on health
issues, investing in improved wastewater management and the

supply of safe water provides particularly high returns.

4

Successful and sustained wastewater management will need an entirely new dimension of investments, to start now

Currently, most of the wastewater infrastructure in many of the
fastest growing cities is lacking. It is outdated, not designed to
meet local conditions, poorly maintained and entirely unable
to keep pace with rising urban populations. Experiences have
shown that appropriate investments done in the right manner
can provide the required returns. However, it will require not
only investments, but careful and comprehensive integrated water and wastewater planning and management at national and
municipal levels. This must transcend the entire water supply
and disposal chain involving ecosystem management (including
coastal waters), agricultural efficiency and production and treatment of wastewater and a stronger focus on urban planning.
11


Wise investments in wastewater
management will generate significant
returns, as addressing wastewater
is a key step in reducing poverty and
sustaining ecosystem services

The policy recommendations presented in part III of this report propose a two-pronged, incremental approach to tackle
immediate consequences whilst thinking to the long term:

A

Tackle immediate consequences

1. Countries must adopt a multi-sectoral approach to wastewater management as a matter of urgency, incorporating principles of ecosystem-based management from the watersheds
into the sea, connecting sectors that will reap immediate
benefits from better wastewater management.
2. Successful and sustainable management of wastewater requires a cocktail of innovative approaches that engage the
public and private sector at local, national and transboundary
scales. Planning processes should provide an enabling environment for innovation, including at the community level
but require government oversight and public management.
3. Innovative financing of appropriate wastewater infrastructure should incorporate design, construction, operation,
maintenance, upgrading and/or decommissioning. Financing should take account of the fact that there are important livelihood opportunities in improving wastewater
treatment processes, whilst the private sector can have an
important role in operational efficiency under appropriate
public guidance.
12

B

Thinking to the long term

4. In light of rapid global change, communities should plan
wastewater management against future scenarios, not current situations.
5. Solutions for smart wastewater management must be socially and culturally appropriate, as well as economically and
environmentally viable into the future.
6. Education must play a central role in wastewater management and in reducing overall volumes and harmful content
of wastewater produced, so that solutions are sustainable.


CONTENTS
5

6
9
15

JOINT STATEMENT
PREFACE
EXECUTIVE SUMMARY
INTRODUCTION

23

PART I
THE CHALLENGES OF WASTEWATER
AND WASTEWATER MANAGEMENT
WASTEWATER AND URBAN LIFE
WASTEWATER, FOOD SECURITY AND
PRODUCTION
WASTEWATER AND INDUSTRY
WASTEWATER, HEALTH AND HUMAN
WELLBEING
WASTEWATER AND ECOSYSTEM FUNCTION
WASTEWATER AND GLOBAL CHANGE

24
30
37
40
43
49
53

54
57

PART II
REALISING THE OPPORTUNITIES OF
WASTEWATER
RECOGNISING WASTEWATER AS A RESOURCE
DEFUSING THE CRISIS: MANAGING
WASTEWATER EFFECTIVELY

73

PART III
POLICY RECOMMENDATIONS

76
80
81
82

GLOSSARY
ACRONYMS
CONTRIBUTORS AND REVIEWERS
REFERENCES

13


14

INTRODUCTION
Water is crucial for all aspects of life, the defining feature of our planet. Ninety seven
and a half per cent of all water is found in the oceans, of the remaining freshwater only
one per cent is accessible for extraction and use. Functioning and healthy aquatic ecosystems provide us with a dazzling array of benefits – food, medicines, recreational amenity,
shoreline protection, processing our waste, and sequestering carbon. At the beginning
of the 21st century, the world faces a water crisis, both of quantity and quality, caused by
continuous population growth, industrialization, food production practices, increased
living standards and poor water use strategies. Wastewater management or the lack of,
has a direct impact on the biological diversity of aquatic ecosystems, disrupting the fundamental integrity of our life support systems, on which a wide range of sectors from
urban development to food production and industry depend. It is essential that wastewater management is considered as part of integrated, ecosystem-based management that
operates across sectors and borders, freshwater and marine.
Fresh, accessible water is a scarce (figure 1) and unevenly distributed resource, not matching patterns of human development. Over half the world’s population faces water scarcity. Because it plays a vital role in the sustenance of all life, water is
a source of economic and political power (Narasimhan, 2008)
with water scarcity a limiting factor in economic and social
development.
International attention has to date, focused on water quantity, the supply of drinking water and increasing access to
sanitation with commitment expressed through the World
Summit of Sustainable Development and the Millennium
Development Goal 7 for Environmental Sustainability, target 10 for safe drinking water and sanitation. 2005 – 2015 is
the international decade for Action “Water for Life” (http://
www.un.org/waterforlifedecade/), with a focus on the International year of Sanitation in 2008 ( />Despite this high profile attention, these issues are proving
difficult to resolve, requiring significant sums for investment, over long periods of time and with jurisdiction often
spread across several government departments. Worldwide,

nearly 900 million people still do not have access to safe water (UNDESA 2009), and some 2.6 billion, almost half the
population of the developing world do not have access to adequate sanitation (WHO/UNICEF, 2010). Over 80 per cent
of people with unimproved drinking water and 70 per cent of
people without improved sanitation live in rural areas (DFID,
2008). This is also only part of the story.

What do we mean by wastewater?
Wastewater can mean different things to different people with a
large number of definitions in use. However this report has taken a broad perspective, and defined wastewater as “a combination of one or more of: domestic effluent consisting of blackwater (excreta, urine and faecal sludge) and greywater (kitchen
and bathing wastewater); water from commercial establishments and institutions, including hospitals; industrial effluent,
stormwater and other urban run-off; agricultural, horticultural
and aquaculture effluent, either dissolved or as suspended
matter (adapted from Raschid-Sally and Jayakody, 2008).
15


World fresh water supply
World fresh water supply

About 97.5% of all water on
About 97.5%saltall water on
Earth is of water
Earth is salt water

Only 2.5% of all the water on
Only Earth is fresh water on
2.5% of all the water
Earth is fresh water

Around 70% of fresh water is
Aroundin Antarctica and
frozen 70% of fresh water is
frozen in Antarctica and
Greenland icecaps
Greenland icecaps

Most of the remaining freshwater
Most of deep underground to be
lies too the remaining freshwater
lies too deep underground to be
accessible or exists as soil
accessible or exists as soil
moisture
moisture

Only 1% of the earth's fresh water is
Only 1% of the earth's fresh human use
available for withdrawal and water is
available for withdrawal and human use

Sources: FAO, 2009.
Sources: FAO, 2009.

Figure 1: Water is the life force of our planet, but only 1 per cent
of all the freshwater on Earth is available for human use.
16

Water is crucial for all aspects of life, the defining feature of our
planet. Ninety seven and a half per cent of all water is found
in the oceans, of the remaining freshwater only one per cent
is accessible for extraction and use. Functioning and healthy
aquatic ecosystems provide us with a dazzling array of services
– food, medicines, recreational amenity, shoreline protection,
processing our waste, and sequestering carbon. At the beginning of the 21st century, the world faces a water quality crisis,
caused by continuous population growth, industrialization,

food production practices, increased living standards and poor
water use strategies. Wastewater management or the lack of,
has a direct impact on the biological diversity of aquatic ecosystems, disrupting the fundamental integrity of our life support
systems, on which a wide range of sectors from urban development to food production and industry depend. It is essential
that wastewater management is considered as part of integrated, ecosystem-based management that operates across sectors
and borders, freshwater and marine.
Access to safe water is a human right (UNDP, 2006). However,
the right to pollute and discharge contaminated water back into


Water withdrawal and use

Water withdrawal
per capita
and its use by sector
Agriculture

Pacific
Oc
Ocean

South Asia

Domestic
Industry

0

Asia
(except South Asia)

Europe

North America

Latin America
and Caribbean

Atlantic
Ocean

Africa

200 400 600 800 1 000

Cubic metres

Indian
Ocean

Oceania

Sources: FAO statistical database, 2009; UNPD, 2009.

Figure 2: Regional variation in water withdrawal per capita and its use by sector.
17


Wastewater, a global problem with differing regional issues

Total fertilizers usage
Million tonnes over
1980-2002 period
Water disease
related deaths
per 100 000 inhabitants
Sources: WHO database, data for
2002; FAO database; Babel et Walid,
2008: European Environment
Agency, 2009; Diaz, R., et al., 2008.

Variation within Europe:
Exceeding critical nutrient loading

less than 15
15 to 30
30 to 100

910

100 to 200
200 to 400
More than 400

370
45

Dead zones

Polluted river basins

Helmand
3

Indus

Eutrophication
equivalents (N) per
hectare and year
None
0 to 200
200 to 400
400 to 700
700 to 1 200
18

Ganges
Brahmaputra
Meghna

55
94

Ecosystem deterioration
parameter *
Severe
High
Wastewater discharge (Billion cubic metres per year)
* Defined as the land ratio without vegetation coverage (forest area
and wetlands) used to present the contribution of an ecosystem’s
deterioration to the vulnerability of its water resources.

the environment, polluting the water of downstream users, is not.
As water travels through the hydrological system from the mountain summit to the sea, the activities of human society capture,
divert and extract, treat and reuse water to sustain communities
and economies throughout the watershed (agricultural, industrial
and municipal) (figure 4). These activities, do not, however return
the water they extract in the same condition. A staggering 80–90
per cent of all wastewater generated in developing countries is discharged directly into surface water bodies (UN Water, 2008).
Unmanaged wastewater can be a source of pollution, a hazard
for the health of human populations and the environment alike.
The Millennium Ecosystem Assessment (MA, 2005) reported
that 60 per cent of global ecosystem services are being degraded
or used unsustainably, and highlighted the inextricable links between ecosystem integrity and human health and wellbeing.
Wastewater can be contaminated with a myriad of different
components (figure 5): pathogens, organic compounds, synthetic chemicals, nutrients, organic matter and heavy metals.
They are either in solution or as particulate matter and are carried along in the water from different sources and affect water
quality. These components can have (bio-) cumulative, persistent and synergistic characteristics affecting ecosystem health
and function, food production, human health and wellbeing,
and undermining human security. Over 70 percent of the water has been used in other productive activities before entering
urban areas (Appelgren, 2004; Pimentel and Pimentel, 2008).
Wastewater management must address not only the urban but
also the rural context through sound and integrated ecosystembased management including, for example fisheries, forestry
and agriculture.
The quality of water is important for the well-being of the environment, society and the economy. There are however ways to
become more efficient and reduce our water footprint. Improving water and sanitation services and managing water require

investment. It is not a question of the quantity of investment.
There are numerous anecdotes pointing to a history of one-off,
short-term, single-sector investments – capital treatment-plant

developments which were unable to secure operation and management funding, built at the wrong scale or in the wrong location. Even without empirical data, it is clear that this approach
is not generating results in either improved water quality or financial incentive.
A paradigm shift is required towards new approaches that include wise investments and technological innovation, not one
size fits all, but now ensuring that investments are appropriate to the industries and communities they serve. Such investments can boost economies, increase labour productivity and
reduce poverty. This report uses a number of case studies to illustrate the challenges of wastewater management, but also the
opportunities for how wastewater management and reuse can
safely meet the growing demands for water resources, without
degrading the environment, and the ecosystem services on
which we depend.

 Figure 3: The significance of wastewater and contents of wastewater vary greatly between and even within regions. In Africa for
example, it is the impact on people’s health that is the major factor, in Europe, the input of nutrients into the coastal waters reducing
productivity and creating anoxic dead zones.
19


Freshwater and wastewater cycle
Water withdrawal and pollutant discharge

Rain
Evapotraspiration

Agriculture
Urban

Rural

Domestic
70%

Sources: WHO; FAO; UNESCO; IWMI.

Figure 4: As water is extracted and
used along the supply chain, both
the quality and quantity of water is
reduced.
20

8%

Industry
22%


Wastewater
Contaminants and their effects
ORIGIN

MANAGEMENT

Storm water
Storm water
Storm water
Sewerage
Sewerage
Sewerage
Industrial
Industrial
Industrial

Spills
Spills
Spills

Centralized and
decentralized sewage
treatment
Combined sewage
and storm water
Individual household
treatment
Reed bed filtration

Manufacturing waste
Manufacturing waste
Manufacturing waste

Global water withdrawal
percentage by sector
Waste water
discharge
Contaminated
food provision
Reusing processed
sewage
Drinking water treatment
Sewage sludge

Nuclear
Nuclear

Nuclear

Enhancing nutrient
filtration of wetlands
Municipality waste
management

Agricultural run off
Agricultural run off
Agricultural run-off

Medical
Medical
Medical

Industrial small scale
waste management

Acquaculture
Acquaculture
Acquaculture

TOXICITY

Smelly
Solid w
Solid waste
Suffocate/block
Poisonous

P
Pharmaceutical
Corrosive

Ecosystem
degradation

I ganic
Inorganic
p
e
particulate
m
material
Radioactive

Organic matter
Biological

Chemicals
Micro
cro
crobes
Microbes

Heavy metals
Infectous

Decreased ecosystem
health (e.g. dead zones)

 Figure 5: The contaminants in waste­

water come from many different sources
and can have cumulative and synergistic
effects requiring a multi-pronged response.

Contaminated
food

Increased
production costs

Decreased
human health

IMPACT

Contaminated
drinking and
bathing water

Source: personal communication with E. Corcoran and E. Baker, UNEP-Grid Arendal.

21


22

PART I
THE CHALLENGES OF WASTEWATER AND WASTEWATER
MANAGEMENT
Wastewater – spent or used water from farms, communities, villages, homes, urban areas or industry may contain harmful dissolved or suspended matter. Unregulated discharge of wastewater undermines biological diversity, natural resilience and the capacity
of the planet to provide fundamental ecosystem services, impacting both rural and urban
populations and affecting sectors from health to industry, agriculture, fisheries and tourism. In all cases, it is the poorest that are the most severely affected.
These impacts continue to grow. Global populations are increasing rapidly and will reach between nine and 11 billion in 2050,
and as population increases so does the production of waste­
water and the number of people vulnerable to the impacts of severe wastewater pollution. Almost 900 million people currently
lack access to safe drinking water, and an estimated 2.6 billion
people lack access to basic sanitation (WHO/UNICEF, 2010).

In this part of the report we will present some of the key challenges that the unregulated discharge of wastewater presents.

Lack of capacity to manage wastewater not only compromises
the natural capacity of marine and aquatic ecosystems to assimilate pollutants, but also causes the loss of a whole array of
benefits provided by our waterways and coasts that we too often
take for granted; safe water for drinking, washing and hygiene,
water for irrigating our crops and producing our food and for
sustaining ecosystems and the services they provide. The financial, environmental and societal costs in terms of human
health, mortality and morbidity and decreased environmental
health are projected to increase dramatically unless wastewater
management is given very high priority and dealt with urgently.
23


WASTEWATER AND URBAN LIFE
Global populations are growing rapidly, particularly so in urban areas where the rate of
urbanization far outstrips planning and wastewater infrastructure development. Existing
wastewater infrastructure of most cities is decaying or no longer appropriate and in slum

areas there is no planning and few facilities. Management of wastewater in the urban
context must be adapted according, not only to the size, but also to the economic development and governance capacity of the urban area. By working together, and cooperating
across municipalities the challenges of addressing wastewater management can be met
and potential benefits realized.
Urban areas are both consumers and producers of large amounts
of wastewater. Providing good quality water and sanitation services to densely populated areas involves significant planning
and infrastructure. Over the next 25 years the annual growth rate

in urban areas is predicted to be twice as high as that projected
for the total population (1.8 per cent versus almost 1 per cent).
As soon as 2030, 4.9 billion people, roughly 60 per cent of the
world’s population, will be urban dwellers (UNDESA 2006).

Access to sanitation facilities
Access to sanitation facilities

Commonwealth of
Independent States
Commonwealth of
Independent States
West Asia

East Asia
East Asia

West Asia

North
Africa
North

Africa

Type of sanitation facility
Shared Unimproved
Type of sanitation facility
Improved
Open
Shared Unimproved
defecation
Improved
Open
defecation

South Asia
South Asia

Latin America
and Caribbean
Latin America
and Caribbean

0

500 1 000 1 500
Million people
0 500 1 000 1 500
Million people

Improved: facilities that ensure hygienic separation of
human excreta from human contact. Includes connection

Improved: facilities that ensure tank, or separation
to a piped sewer system, septic hygienic pit latrines. of
human excreta from human contact. Includes connection
to a piped sewer system, septic tank, or pit latrines.

Atlantic
Ocean
Atlantic
Ocean

Indian
Ocean
Indian
Ocean

SubSaharan
SubAfrica
Saharan
Africa

Eastern Asia
South
Eastern Asia

Oceania
Oceania

Source: JMP, Progress in drinking water and sanitation, 2008.
Shared: sanitation facilities of an otherwise
acceptable type shared between two or

Shared: sanitation
more households. facilities of an otherwise
acceptable type shared between two or
more households.

Source: JMP, Progress in drinking water and sanitation, 2008.
Unimproved: facilities that do not
Open defecation: in fields, forests, bushes,
ensure hygienic separation of
bodies of water or other open spaces, or
Unimproved: from human contact
Open defecation: in fields, forests, bushes,
human excretafacilities that do not
disposal of human faeces with solid waste.
ensure hygienic separation of
bodies of water or other open spaces, or
human excreta from human contact
disposal of human faeces with solid waste.

Figure 6: Access to improved sanitation remains a pressing issue in many regions.
24

Pacific
a ic
c
O an
Ocean
Ocean
Pacific
a ic

c
South
O an
Ocean
Ocean


Most of the rapid expansion in urbanization is taking place
not in megacities, but in small and medium sized cities with
populations of less than 500  000 (UNFPA, 2007). Growth
is often unplanned and attracting government and private
investment to infrastructure development in areas that lack
the economic clout of the megacities is difficult. In addition,
an estimated one billion people currently live in urban slums
without even the most basic services (UN-HABITAT, 2009).
Because these informal settlements lack land tenure, provid-

ing water and sanitation services through investment in large
infrastructure is extremely difficult.
Water and wastewater services are often controlled by multiple
authorities operating at a local, regional or national level. The
infrastructure may be state-owned or include private sector
involvement. The reliance of traditional wastewater-treatment
systems on large-scale infrastructure generally results in a
natural monopoly and hence a lack of market competition.

Centralized or decentralized?
Uganda. A study case

Centralized sewage and wastewater connection

Present Net Value
US Dollars, 2006

Financial NPV
Economic NPV

0

Decentralized latrines with excreta reuse
Using low price latrines
Using high price latrines

Economic Present Net Value
US Dollars, 2006
400
300

-200

200

-400

100

-600

0

-800

-100

-1 000

-200

-1 200

Note: the Present Net Value (PNV) measures the
resultant financial and economic benefit of goods
or services when all costs and benefits are taken
into consideration. A positive NPV indicates a net
benefit and a negative NPV a net loss.

-1 400
-1 600
1 000

2 500
5 000
10 000
Population connected to the sewer

-300
-400
-500
-30

-20

-10

0

10

20

30

Change in food price, percentage

Source: WSP, Study for Financial and Economic Analysis of Ecological Sanitation in Sub-Saharan Africa, 2006.

Figure 7: Looking at the costs and benefits, centralized systems may not be the answer in terms of best result for the investment. The
chart on the left shows that the financial NPV does not change with increasing population size for centralized sewage and wastewater
connection, however the economic NPV (which includes benefits to health and the environment) shows a positive trend with increasing populations. Centralized systems therefore generate a greater benefit as population increases, but show a significant loss with
small community size. The chart on the right shows the situation where decentralized latrines have been installed, and where the
excreta is reused for food production, and hence the overall benefits returned will depend on the current market price for food. With
a good market, the reuse benefits of low-cost latrines can be realized by the households into a positive NPV, however those requiring
greater investment, do not offer a return on the investment (WSP, 2006).
25